It is known that an access point device can be the coordinator, center, and initiator of an IEEE 802.15.4 based low power wireless personal area network (WPAN). However, due to the limitations of wireless protocols and the limited memory in access point devices, the number of wireless sensor devices connected to a single access point device is limited. For example, some known access point devices can be connected to 64 sensor device nodes or 128 sensor device nodes. In known RF6 WPANs, one access point device can support 128 sensor device nodes.
When known commercial wireless systems require and support hundreds or thousands of sensor devices, multiple access point devices are required to connect the sensor devices. Therefore, the multiple access point devices must also be connected to a control panel device in a corresponding wired or wireless manner. For example, as seen in FIG. 1, the access point devices AP1-AP8 can be connected to the control panel device 100 via a wired or wireless data bus 110, and each of the access point devices AP1-AP8 can coordinate a respective WPAN for connecting to a respective plurality of sensor devices. In known RF6 WPANs, the control panel device can support 1024 sensor device nodes by connecting eight access point devices. However, such configurations present the problem of synchronizing the WPANs of the multiple access point devices to achieve a time critical feature, such as a One Go All Go feature.
When the One Go All Go feature is achieved and there is an emergency alarm in the system, such as a smoke alarm or a carbon monoxide (CO) alarm, sounder devices in the sensor devices, such as smoke detectors or CO detectors, are activated and synchronized with the temporal pattern alarm cadence of other sensor devices and siren devices installed in the same system. For example, the sensor devices can be synchronized with a temporal pattern 3 alarm cadence during the smoke alarm, which is graphically depicted in FIG. 2 and requires accuracy of +/−50 ms. Similarly, the sensor devices can be synchronized with a temporal pattern 4 alarm cadence during the CO alarm, which is graphically depicted in FIG. 3 and requires accuracy of +/−10 ms. However, when the sensor devices are connected to the control panel device via multiple access point devices, achieving such synchronization can be difficult.
In view of the above, there is a continuing, ongoing need for improved systems and methods.